Both the request and reply versions of this message are not documented on the site.

Client -> Server:
[code](BYTE[32])  Client Public Key   ("A")
(STRING)    Username[/code]

Server -> Client:
[code](DWORD)     Result
(BYTE[32])  Salt                ("s") (zeroed on error)
(BYTE[32])  Server Public Key   ("B") (zeroed on error)

Possible result codes:
    0x00:   OK, proceed to SID_AUTH_ACCOUNTCHANGEPROOF (0x56).
    0x01:   Error: Account does not exist.
    0x05:   Error: Account requires upgrade. (?)[/code]

Thanks.

This message is for password change, right?

Correct.

Thanks. I've added this material as well. Now we can all change our passwords :)

Thanks shady!